Re: [PATCH v4 0/5] pci-hyperv: Fix race condition bugs for fast device hotplug

[Wei Liu]

On Wed, Jun 14, 2023 at 09:44:46PM -0700, Dexuan Cui wrote:
> Before the guest finishes probing a device, the host may be already starting
> to remove the device. Currently there are multiple race condition bugs in the
> pci-hyperv driver, which can cause the guest to panic.  The patchset fixes
> the crashes.
> 
> The patchset also does some cleanup work: patch 3 removes the useless
> hv_pcichild_state, and patch 4 reverts an old patch which is not really
> useful (without patch 4, it would be hard to make patch 5 clean).
> 
> Patch 6 in v3 is dropped for now since it's a feature rather than a fix.
> Patch 6 will be split into two patches as suggested by Lorenzo and will be
> posted after the 5 patches are accepted first.
> 
> The v4 addressed Lorenzo's comments and added Lorenzo' Acks to patch
> 1, 3 and 5.
> 
> The v4 is based on v6.4-rc6, and can apply cleanly to the Hyper-V tree's
> hyperv-fixes branch.
> 
> The patchset is also availsble in my github branch:
> https://github.com/dcui/tdx/commits/decui/vpci/v6.4-rc6-vpci-v4
> 
> FYI, v3 can be found here:
> https://lwn.net/ml/linux-kernel/20230420024037.5921-1-decui@xxxxxxxxxxxxx/
> 
> Please review. Thanks!
> 
> 
> Dexuan Cui (5):
>   PCI: hv: Fix a race condition bug in hv_pci_query_relations()
>   PCI: hv: Fix a race condition in hv_irq_unmask() that can cause panic
>   PCI: hv: Remove the useless hv_pcichild_state from struct hv_pci_dev
>   Revert "PCI: hv: Fix a timing issue which causes kdump to fail
>     occasionally"
>   PCI: hv: Add a per-bus mutex state_lock

Applied to hyperv-fixes. Thanks.